This invention relates generally to the refurbishment of pile carpet, especially carpet tiles, to provide extended wear life without a detrimental affect on the surroundings due to a reduced aesthetic effect by the existing pile carpet due to dirt and/or matting of the pile on the face of the tile. More particularly, this invention relates to a method and apparatus for treating the pile face and/or applying a new layer of material to the back surface of a refurbished carpet tile to create a new like appearance for the back surface of the tile.
As described in U.S. Pat. Nos. 5,381,592 and 5,457,845 hereby incorporated by reference, in the past it has been necessary to replace pile carpet when it became dirty, develops a change in texture in some areas and/or is matted down due to traffic and/or furniture thereon. The replacement of such carpet is expensive due to the price of new carpet and has to be matched to the existing environment. This replacement of carpet, especially carpet tiles, in commercial establishments is an expense which, if it can be avoided, will free up money which can be used for other desirable purposes.
The above described U.S. Pat. Nos. 5,381,592 and 5,457,845 provide a method and apparatus to refurbish cut and loop pile carpet and eliminate the cost of replacement of such tile with new carpet.
In particular, they describe a system wherein pile carpet tiles are refurbished. The invention is directed in general to pile carpet, cut or loop, but is primarily directed to carpet tiles since these are used in commercial establishments and generally receive more wear due to traffic by pedestrians thereon and therefore tend to mat and get dirty quicker than residential carpet. The carpet tiles are usually in 18 inch squares and have pile yarns, cut or loop, like that shown in U.S. Pat. No. 4,371,576 hereby incorporated by reference. As shown in FIG. 1, the carpet tiles 10 are treated on cooperating conveyors 12 and 14 but, obviously, one continuous conveyor could be used, if desired.
Briefly, the system of FIGS. 1 and 2 will be described with the description being directed to a cut pile carpet tile 10. The dirty and/or matted carpet tile 10 is placed on the conveyor 12 where it is initially conveyed under a source of high pressure cleaning liquid or water, generally designated 16, whereat liquid, such as water, is supplied at a pressure within the range of 200-2000 p.s.i.g., preferably 300-1200 p.s.i.g. In one example, the liquid is supplied at a pressure of about 800 p.s.i.g. from the nozzles 18 and impinges on the carpet tile. It is contemplated that an elongated slot can be used rather than the disclosed nozzles 18 so long as the liquid pressure is maintained in the desired range. The high pressure liquid from the jets clean the dirt from the surface and between the yarns 20 of the carpet tile while at the same time removing the twist from the yarn and causing them to upright themselves. From the high pressure water source 16, the carpet tiles pass under a vacuum extractor 22 to remove water therefrom. Also, located under the conveyor 12 is a water sump collector 24 to recover the water from the water source 16.
Since the high pressure water from the nozzle 18 removes the twist from the yarn 20, if the yarn 20 has twist therein, or lifts and straightens yarn which has no or very little twist therein, the surface of the upright yarns tends to be uneven. So the carpet tiles, after being deposited on the conveyor 14 are conveyed to a shear 26, after passing through a dryer 28, to even out the pile height of the yarns 20. If desired, the carpet tiles 10 can be over-printed or brightened by a dye machine 30 prior to being collected on a pallet 32. The dye machine can be of any suitable type but is preferably a computer controlled jet type such as that shown and disclosed in U.S. Pat. No. 4,993,242 hereby incorporated by reference.
The above description is directed to a cut pile carpet but obviously the above system can be employed to clean and de-mat a loop pile carpet tile. One approach, includes cutting of the loops in the loop pile product and then treating it as a cut pile carpet tile as described above. Another approach is to pass the loop pile carpet tile under the high pressure water source as described above but pivot the shear 26, as shown, upwards away from the conveyor 14 as it passes downstream.
To properly maintain the carpet tiles in spaced relationship a plurality of slats 34 are connected to the conveyor 12 and/or 14. As the tiles 10 are conveyed under the high pressure water source a chambered guide bar 36 mounted on both sides of the conveyor guides the carpet tile into position under the water source 16 as the slats 34 pass under the guide bars. This same arrangement can be used on the conveyor 14 as the carpet tiles pass under the shear 26 and the dye machine 30. The slats 34 and the guide bars 36 serve the further function of maintaining the fibers on the edges of the tile in an upright condition as the liquid impinges thereon so that further operations downstream will treat them as well as the other yarn in the body of the tile. This prevents the edge fibers from being bent over and giving a ragged appearance to the carpet tile after cleaning thereof.
FIG. 2 depicts an overall view of the apparatus to apply high pressure water to the carpet tiles, which is depicted as numeral 16, which is characterized in more detail in FIGS. 3 and 4. Pump 36 is used to pump, via suitable conduits 38 and 40, a working fluid such as water from a suitable source of supply 42 through an appropriate filter 44 to a high pressure supply duct 46, which in turn supplies water at suitable dynamic pressure (e.g., between 200 p.s.i.g. to 2000 p.s.i.g.) to the apparatus 16. The fluid thereby emanates from the apparatus 16 thereby striking the carpet tile 10 placed on the conveyor 12.
Looking to FIG. 3, it may be seen that the high pressure water source 16 is comprised of three basic structures: a high pressure supply gallery assembly 48 (which is mounted in operable association with the high pressure supply duct 46), slotted chamber assembly 50 and clamping assembly 52.
Supply assembly 48 constitutes an “L”-shaped member, into one leg of which is machined a uniform notch 56 which extends, uninterrupted, along the entire length of the apparatus 16. There is a rectangular uniform notch 58 which is in the other vertical leg of the “L”-shaped member 54 and adjacent to the high pressure supply duct 46. A series of uniformly spaced supply passages 60 are drilled through the rectangular uniform notch 58 and extend to the corresponding side wall of notch 56, whereby notch 56 may be supplied with high pressure water from high pressure supply duct 46, the side of which may be milled, drilled, and connected to notch 58 which is along the side wall 62 of the assembly 54. Slotted chamber assembly 50 is comprised of dual elongate “U”-shaped members 63, 65 having a rectangular cross-section therebetween. The upper “U”-shaped member 63 has a series of machined closely spaced slots which form the nozzle 18, each having a width approximately equal to the width of the desired high velocity treatment stream.
Referring now to FIGS. 3 and 4, grooved chamber assembly 50 is positioned, via clamping assembly 52, within supply gallery 54 so that its rectangular cross-section communicates via parallel spaced holes 60 to notch 56 which thereby forms both an upper and lower high pressure distribution reservoirs, respectively, so that fluid enters from a supply duct 46 and then into a high pressure distribution reservoir formed by notch 58. The water then travels via supply passages 60 into a lower high pressure distribution reservoir formed by notch 56 and then goes through holes 70 into an upper high pressure distribution chamber 72 formed by dual elongate “U”-shaped members 63 and 65. Water then flows through slots 18 towards the carpet tile 10. Clamping assembly 52 is provided along its length with jacking screws 78 as well as bolts 80 which serve to securely attach clamping assembly 52 to supply gallery assembly 48.
As shown in FIG. 4, the high pressure water source 16 is connected to the high pressure supply gallery assembly 48 by means of bolts 82 and 84 respectively. There are a series of bolts 86 which connect the lower “U”-shaped member 65 with the upper “U”-shaped member 63.
The means of eliminating dirt and mats from the carpet tiles involves the nozzles 18. In the preferred embodiment, there are forty nozzles per inch, but this can vary. Instead of having all of the slots parallel to each other, the nozzles between one lateral edge of the member 63 are at an angle from the longitudinal axis of the member 63. The angle deviation from the longitudinal axis of the member 63 that provides good results is five degrees. This angle can vary widely, with the optimal deviation angle depending on the type of fabric utilized.
In accordance with the present invention, the pile face yarns of used carpet tile, or other flooring, is cleaned and re-textured using the above described methods and apparatus. After drying in a conventional oven, a thin layer of modified acrylic material is applied to the back surface of the refurbished carpet tile using roll applicators, thereby creating a new appearance, a new coated product, and refurbishing the back of the used tile.
The tile is subsequently dried in an oven to remove water and cross-link the acrylic polymer. The acrylic-coating layer when cross-linked, bonds to the original tile back and is highly resistant to chemical plasticizers commonly used for PVC backed carpet tile. The new backing layer forms a protective or blocking layer against plasticizer migration, thereby providing unique product attributes for refurbished carpet tile. Tiles may be re-colored using a textile dyeing or pattern process without adversely effecting the renewed tile back.
In accordance with a preferred embodiment of the present invention, two (2) top roll applicators are used to apply a thin layer of material (approximately 2.0 mm) to the back of the cleaned tile. The applicators are modified to use soft grooved coating rolls (40 durometer shore hardness) and thereby to achieve low coating weights. Depending on the type of carpet tile, approximately 0.50-1.0 oz of coating material per square yards is applied to the back of the carpet tile during the renewal process.
A low temperature cross-linking agent allows the backing or coating to dry and cross-link at 175° F., thereby avoiding damage to the underlying PVC backing materials by overheating.
The following patents are hereby incorporated by reference:
Patent No.DescriptionDate5,381,592Method to Refurbish Carpet TileJan. 17, 19955,457,845Apparatus to Refurbish Carpet TileOct. 17, 19954,808,191Process for Pattern Dyeing of TextileFeb. 28, 1989Material4,740,214Process for Pattern Dyeing of TextileApr. 26 1988Material
Although various methods and apparatus for cleaning and reconditioning articles with pile fibers may be used, the present invention is especially adapted for use with methods and apparatus described in above mentioned U.S. Pat. Nos. 5,381,592 and 5,457,845. These methods and apparatus have been shown to be effective in removing dirt and/or matting of pile face yarns from used carpet tile. Other methods and apparatus for cleaning and reconditioning pile articles may work for particular articles, but they are not usually practical for refurbishing used carpet tile, which are essentially flat articles. In cases where another device or method can be adapted for carpet tile, the typical cleaning pressures employed are found to be too low to achieve the desired yarn re-texturing and removal of dirt and/or matting of the pile face yarns.
Notwithstanding the success of the methods and apparatus of the above referenced patents at cleaning and refurbishing the top of the carpet tile, such are improved by adding a method to effectively clean and refurbish the back surface of the used tile. It is common that the back surface of used carpet tiles are dirty and often coated with layers of old installation adhesives. These materials are typically water insoluble and difficult to remove using conventional methods. Residual adhesives and embedded dirt or floor materials often remain on the back surface of the tile after the prior refurbishment treatment, thereby making refurbished carpet tile difficult and to re-install. Customers often object to the appearance and condition of the back surface, essentially viewing the product as a used carpet. In the past, refurbished carpet tile was not acceptable to some customer for this reason alone.
These same conditions cause difficulties in processing tiles through the refurbishment treatment. The conditions increase the number of rejects and reduce the product yields, thereby making the process more costly. In worst case situations, particular used carpet tile can not successfully be refurbished due to the condition of the tile backing.
It is object of this invention to provide an improved carpet tile refurbishment process whereby after cleaning and re-texturing the pile face yarns of used carpet tile, a new layer of material is applied to the back surface of the tile, thereby renewing the back of the used carpet tile.
With respect to the prior art, no apparatus or method is provided to clean or refurbish the back surface of the tile. Renewing the back surface of the tile in accordance with the present invention provides the benefits listed below. The unique attribute of the applied material to resist chemical plasticizers provides product benefits and features for new and/or refurbished PVC carpet. The material applied to the back of the tile is novel in that the material bonds to all materials commonly used in carpet tile backing systems, to PVC and polypropylene backs. Further, the material is unique in that is provides high resistance to steam and water, and is compatible with adhesives used to install carpet tile.
Benefits
1. Improved aesthetics—both surfaces of the used carpet tile are refurbished. The product is more generally acceptable to more customers.
2. Ease of Installation—the renewed backing layer covers over residual adhesive and embedded dirt or other material, thereby facilitating re-installation of used tile after refurbishment.
3. Lower rejects and improved process yields over the prior process.
4. Coating material that when applied to back surface of new or used tile provides high resistance to chemical plasticizers commonly used for PVC carpet tile. The new backing layer forms a barrier layer against plasticizer migration, a problem common to PVC product, that can result in much higher expenses for carpet tile installation.
5. Coating material that provides high resistance to steam and water, thereby making it possible to dye refurbished carpet tile by conventional textile dyeing methods.
6. Coating material that is compatible with commonly used installation adhesives.
7. Coating material that bonds all known commercially used carpet-backing materials including polypropylene and PVC backing.
8. Coating material that is low in VOC and therefore meets or exceeds industry standards for indoor air quality for carpeting.
Other acrylic polymers and cross-linking agents may provide similar or like results. Certain polyurethane materials may be suitable for the backing renewal of used carpet tile, but in general tend to be more expensive than modified acrylic polymers.
Other application devices may be used to apply the coating material. These methods include rod or engraved roll applicators, used either as a single applicator or as multiple applicators.
Different thickness and weights of materials may be applied to the back surface of the tile.
The following is a preferred embodiment of the process of the present invention: